1. Field of the Invention
The present invention generally relates to synchronization-based communication systems and, more particularly, to communication systems based on synchronization of chaotic dynamical systems.
2. Background Description
The simplest communication systems consist of a transmitter and a receiver. Such a simple setup can only work if the communication medium does not alter the information signal. In most practical systems however, the communication medium alters the signal and introduce disturbances in a variety of ways. Examples of such practical systems include radio communications, television broadcasts, etc. In such cases, one or both ends of the communication system will need to be equipped with circuitry to overcome the problems caused by these disturbances.
The present invention relates to the problem of communication through noisy channels. A general method to allow transmitted signals to resist noise and other disturbances is spread spectrum communication, whose foundations lies in spectral analysis. This method appears in various forms with different levels of sophistication, depending for example on the signal to noise ratio (S/N) that the communication must accommodate in various settings (see for example, Robert C. Dixon, Spread Spectrum Systems With Commercial Applications, John Wiley & Sons, 1994, and Andrew J. Viterbi, CDMA Principles of Spread Spectrum Communication, Addison-Wesley, 1995). The basic idea is to spectrally spread a signal so that, even if the noise is at times very disturbing in some bands, enough of the information can be recovered.
The present invention offers an alternative to more classical spread spectrum communication techniques in settings where transmitted digital signals are recovered using correlation properties. The classical approach needs precise synchronization to be implemented in order to recognize binary sequences, and is heavily digital. The present invention has automatic synchronization built in, does not require correlation analysis (although correlators could be used as an alternative of or in combination with the proposed technique of demodulation), and is mostly analog, which allows higher coding frequencies. Nevertheless, the system is sufficiently digital to allow the quality of the detection to be enhanced by using error correcting codes.